  Signal - Signal manual description
  analpf - create analog low-pass filter
  buttmag - response of Butterworth filter
  casc - cascade realization of filter from coefficients
  cepstrum - cepstrum calculation
  cheb1mag - response of Chebyshev type 1 filter
  cheb2mag - response of type 2 Chebyshev filter
  chepol - Chebychev polynomial
  convol - convolution
  corr - correlation, covariance
  cspect - spectral estimation (correlation method)
  czt - chirp z-transform algorithm
  detrend - remove constant, linear or piecewise linear trend from a vector
  dft - discrete Fourier transform
  ell1mag - magnitude of elliptic filter
  eqfir - minimax approximation of FIR filter
  eqiir - Design of iir filters
  faurre - filter computation by simple Faurre algorithm
  ffilt - coefficients of FIR low-pass
  fft - fast Fourier transform.
  ifft - fast Fourier transform.
  fft2 - two-dimension fast Fourier transform
  fftshift - rearranges the fft output, moving the zero frequency to the center of the spectrum
  filter - modelling filter
  find_freq - parameter compatibility for elliptic filter design
  findm - for elliptic filter design
  frfit - frequency response fit
  frmag - magnitude of FIR and IIR filters
  fsfirlin - design of FIR, linear phase filters, frequency sampling technique
  group - group delay for digital filter
  hank - covariance to hankel matrix
  hilb - Hilbert transform
  iir - iir digital filter
  iirgroup - group delay Lp IIR filter optimization
  iirlp - Lp IIR filter optimization
  intdec - Changes sampling rate of a signal
  jmat - row or column block permutation
  kalm - Kalman update
  lattn - recursive solution of normal equations
  lattp - lattp
  lev - Yule-Walker equations (Levinson's algorithm)
  levin - Toeplitz system solver by Levinson algorithm (multidimensional)
  lgfft - utility for fft
  lindquist - Lindquist's algorithm
  mese - maximum entropy spectral estimation
  mfft - multi-dimensional fft
  mrfit - frequency response fit
  %asn - elliptic integral
  %k - Jacobi's complete elliptic integral
  %sn - Jacobi 's elliptic function
  phc - Markovian representation
  pspect - cross-spectral estimate between 2 series
  remez - Remez's algorithm
  remezb - Minimax approximation of magnitude response
  rpem - RPEM estimation
  sinc - samples of sinc function
  sincd - digital sinc function or Direchlet kernel
  srfaur - square-root algorithm
  srkf - square root Kalman filter
  sskf - steady-state Kalman filter
  system - observation update
  trans - low-pass to other filter transform
  wfir - linear-phase FIR filters
  wiener - Wiener estimate
  wigner - 'time-frequency' wigner spectrum
  window - compute symmetric window of various type
  yulewalk - least-square filter design
  zpbutt - Butterworth analog filter
  zpch1 - Chebyshev analog filter
  zpch2 - Chebyshev analog filter
  zpell - lowpass elliptic filter